Energy Saving and Interference Cancellation in the WLAN with a Full-Duplex Access Point

This paper investigates the problem of minimizing power consumption under the situation of eliminating the uplink-downlink interference (UDI) through the IC2 technique for a full-duplex WLAN where half-duplex users communicate with the full-duplex AP. In particular, the problem formulation is to minimize the power consumption of half-duplex users and the full-duplex AP in the system while guaranteeing the required data rate of both the uplink and downlink users. The formulated problem falls into a mixed integer nonlinear programming (MINLP) form, which is generally NP-hard to solve. To make the problem tractable, we divide it into user pairing and power allocation sub-problems. Specifically, we devise a user pairing criterion based on the signal-to-interference-plus-noise ratio (SINR) to reduce the interference at downlink users incurred by the uplink transmission, thus decreasing the power that used to eliminate the interference. After that, we adjust the transmit power of both users and the AP to minimize the total power consumption under the constraint of users' minimum data rate requirements. Simulation results are presented to evaluate the performance of our scheme and demonstrate the power consumption reduction compared to other schemes in full-duplex WLANs.